Mielke Stefan, Zimmer Marlene, Meena Mukesh Kumar, Dreos René, Stellmach Hagen, Hause Bettina, Voiniciuc Cătălin, Gasperini Debora
Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland.
Sci Adv. 2021 Feb 10;7(7). doi: 10.1126/sciadv.abf0356. Print 2021 Feb.
Despite the vital roles of jasmonoyl-isoleucine (JA-Ile) in governing plant growth and environmental acclimation, it remains unclear what intracellular processes lead to its induction. Here, we provide compelling genetic evidence that mechanical and osmotic regulation of turgor pressure represents a key elicitor of JA-Ile biosynthesis. After identifying cell wall mutant alleles in () with elevated JA-Ile in seedling roots, we found that ectopic JA-Ile resulted from cell nonautonomous signals deriving from enlarged cortex cells compressing inner tissues and stimulating JA-Ile production. Restoring cortex cell size by cell type-specific KOR1 complementation, by isolating a genetic suppressor, and by lowering turgor pressure with hyperosmotic treatments abolished JA-Ile signaling. Conversely, hypoosmotic treatment activated JA-Ile signaling in wild-type plants. Furthermore, constitutive JA-Ile levels guided mutant roots toward greater water availability. Collectively, these findings enhance our understanding on JA-Ile biosynthesis initiation and reveal a previously undescribed role of JA-Ile in orchestrating environmental resilience.
尽管茉莉酰异亮氨酸（JA-Ile）在调控植物生长和环境适应性方面发挥着至关重要的作用，但其诱导产生的细胞内过程仍不清楚。在此，我们提供了令人信服的遗传学证据，表明膨压的机械和渗透调节是JA-Ile生物合成的关键激发因素。在鉴定出（）中幼苗根中JA-Ile含量升高的细胞壁突变等位基因后，我们发现异位JA-Ile是由来自扩大的皮层细胞压缩内部组织并刺激JA-Ile产生的细胞非自主信号引起的。通过细胞类型特异性的KOR1互补恢复皮层细胞大小、分离遗传抑制因子以及用高渗处理降低膨压，均消除了JA-Ile信号传导。相反，低渗处理激活了野生型植物中的JA-Ile信号传导。此外，组成型JA-Ile水平引导突变根趋向于更高的水分可利用性。总体而言，这些发现增进了我们对JA-Ile生物合成起始的理解，并揭示了JA-Ile在协调环境适应性方面以前未被描述的作用。
